This review assessed system changes to counteract the effects of physician work hours, fatigue or sleep deprivation on patient safety outcomes. The authors concluded that the evidence presented was insufficient to inform practice. Their conclusions and recommendations for further research are appropriate given the limitations of the current evidence.

Authors' objectives

To evaluate whether adhering to the Accreditation Council for Graduate Medical Education (ACGME) standards for resident work hours would improve patient safety outcomes.

Searching

MEDLINE, EMBASE and Current Contents were searched from 1966 to March 2004 using the search terms reported. Several journals were handsearched (a full list was given in the paper). The reference lists of all articles included in the review and review articles were examined to identify additional papers. An expert was asked to review the final bibliography. Both published and unpublished material was eligible for inclusion, but studies were limited to those published in English.

Study selection

Study designs of evaluations included in the review

No criteria for study design were specified.

Specific interventions included in the review

The studies needed to assess a system change designed to counteract the effects of work hours, fatigue or sleep deprivation. The interventions used were float systems, other cross-coverage systems, or unspecified schedule changes.

Participants included in the review

Inclusion criteria for the participants were not stated. The participants included were interns and residents. 'Interns' were defined as physicians in their first year of postgraduate training, while 'residents' were defined as those in at least their second year of training.

Outcomes assessed in the review

The studies needed to include an outcome directly related to patient safety (e.g. death, morbidity and patient care errors).

How were decisions on the relevance of primary studies made?

Two authors independently reviewed the articles from the first search (1966 to 2002), while one author reviewed the articles from the second search (2002 to 2004) using the same criteria.

Assessment of study quality

A formal validity assessment does not appear to have been undertaken, but the authors did discuss the strengths and weaknesses of each study.

Data extraction

Two authors were involved in the data extraction and one author reviewed all the studies. A standardised data extraction form, covering number of participants, presence or absence of a control group, study design, outcomes and methodological concerns, was used. All disagreements were resolved by consensus. Where necessary, the authors of the studies were contacted for additional information.

Methods of synthesis

How were the studies combined?

The studies were combined in a narrative summary.

How were differences between studies investigated?

Differences between the studies were discussed within the report.

Results of the review

Seven studies were included: 5 cohort studies, one pre-post study and one case-control study. The numbers of participants were not stated.

In the 5 studies that assessed mortality and morbidity there were no differences in rates between either intervention and control hospitals, or before and after the implementation of a change in working hours or system of shift cover. For the outcomes of medication errors, readmissions and resource utilisation (length of stay, consultations, procedure and radiographs), the interventions had an unclear effect, with some indicators not changing and others improving or worsening across the 5 studies reporting on one or more of these outcomes.

Authors' conclusions

Evidence on patient safety was insufficient to inform the process of reducing resident working hours.

CRD commentary

The inclusion criteria for the interventions and outcomes were stated, but those for the participants and study designs were unclear. The search was based on a range of electronic databases and other sources, although the restriction to English language studies raises the possibility of language bias. A formal validity assessment does not appear to have been conducted, but the strengths and weaknesses of each study were highlighted. The narrative synthesis of the literature was appropriate given the diversity of the studies. In view of the limitations of the evidence presented, the authors appropriately highlighted the need for further, better quality research.

Implications of the review for practice and research

Practice: The authors advocated caution in believing that conforming to the ACGME guidelines would improve patient safety.

Research: The authors stated that research funding must be made available to study policy-change decisions such as those in the included studies; patient safety outcomes should be evaluated; an investigation should be conducted across several institutions; and the interventions should be as similar as possible to allow pooling of the data. Randomised controlled trials should be conducted where possible or potential, confounding variables should be adjusted for. Research into discontinuity between admission and the remainder of the hospitalisation versus discontinuity in the hour-to-hour care of patients may be appropriate.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.